1. Field of the Invention
The present invention relates to a small card adaptor into which a small card is inserted so as to be connected to a host apparatus.
2. Description of the Related Art
Recently, small cards are being used in personal computers, digital cameras, PDA (Personal Digital Assistance), handy terminals (data recording apparatus having a function of inputting data on the spot and sending data through a communication line or the like), and the like. In digital cameras, SD (Secure Digital) memory cards and the like that do not comply with the PC card ATA standards interface are used often as small memory cards for the purpose of storing image data. Small card adaptors for allowing image data stored in such small memory cards to be read/rewritten by personal computers also are used often. Furthermore, in the PDA, small communication cards such as SD card type small cards with a PHS (Personal Handy phone System) built therein, which do not comply with the PC card ATA standards interface, are used for the Internet and mail. Small card adaptors allowing the same small communication cards to be used in personal computers are used often.
In a conventional small card adaptor with a small memory card inserted therein, through a register group complying with the PC card ATA standards interface, a control program or a control logic of a controller provided in the small card adaptor interprets an instruction such as writing and reading of data from a host computer, converts the instruction into a command that can be interpreted by the inserted small memory card, and issues the converted command to the small memory card.
For example, when a small card adaptor with a SD memory card inserted therein is connected to a host computer with a Windows (Trade Name) OS mounted thereon, the host computer reads CIS (Card Information Structure) information based on the PC card ATA standards interface described in a PC Card Standard from the small card adaptor. Then, the host computer selects driver software for the PC card ATA standards interface of the OS, based on the read CIS information. Then, in the case where the host computer instructs the small card adaptor to write the data of an image file, the small card adaptor uses a control program provided therein to interpret the contents of the instruction, create a command code to be written in a region called a Command Index and a value of a parameter such as an Argument used with the command code in the small card adaptor, and give an instruction to the small memory card. Furthermore, the small card adaptor returns the results of the processing by the small memory card to the host computer through the PC card ATA standards interface. Thus, an image file can be stored and read.
In a conventional small card adaptor for data communication, a control program of a memory provided in a small communication card adaptor is rewritten in accordance with a wireless telephone apparatus to be connected, and data communication processing can be performed in accordance with the rewritten control program (e.g., see JP 2000-92147 A).
Furthermore, as an application, there is a small card adaptor capable of being connected to a small communication card instead of a wireless telephone apparatus. As an interface for a small card adaptor to be electrically connected to a host computer, a serial port interface for a modem or a network adaptor interface for a LAN card is used.
For example, when a small card adaptor with a SD card type small card containing a PHS communication function inserted therein is connected to a host computer with a Windows OS mounted thereon, CIS information for a serial port interface described in a PC Card Standard is read from a small card adaptor, and the host computer selects driver software for a serial port of an OS, based on the read CIS information. Then, in the case where the host computer instructs the small card adaptor to write data in a Transmitter Holding Register, the small card adaptor uses a control program provided therein to interpret the contents of the instruction, create a command code to be written in a region called a Command Index and a value of a parameter such as an Argument used with the command code in the small card adaptor, and give an instruction to the SD card type small card in which a PHS communication function is built.
Furthermore, the small card adaptor returns the results of the processing by the SD card type small card with a PHS communication function built therein to the host computer using a serial port interface of the small card adaptor. Thus, the Internet and electronic mail can be used.
However, in the above-mentioned conventional small card adaptor into which a small communication card is inserted is varied in terms of specifications due to the difference in the kind and function of small communication cards to be inserted. Therefore, it is required to change a control program and a control logic of a controller stored in a memory provided in the small card adaptor on the basis of the difference in the kind and function of small communication cards.
An example will be described regarding the above problem. Parameters such as a Command Index and an Argument set for access to a SD card type small card with a PHS communication function built therein, developed by A company cannot be used for a SD card type small card with a PHS communication function built therein and a SD card type small card with a wireless LAN communication function built therein, developed by B company. Therefore, it is required to write and hold a control program changed so as to be compatible with the parameters such as a Command Index and an Argument in a memory provided in a small card adaptor. Therefore, when the capacity of a memory provided in the small card adaptor is small, there is a possibility that the function of the control program may be limited. In contrast, when the function of the control program is set so as to be expanded, it is necessary to increase the capacity of a memory. Therefore, a small card adaptor may become expensive.
Furthermore, conventionally, a user having both a small communication card and a small memory card needs to own both a small card adaptor for a small communication card and a small card adaptor for a small memory card. Therefore, it is inconvenient to carry and handle a small card adaptor.
In the above case, producing a small card adaptor capable of using both a small communication card and a small memory card might be considered. However, a small card adaptor for a small communication card and a small card adaptor for a small memory card are composed of a register group based on different respective interfaces. Therefore, when a small communication card is inserted, it is necessary to set a small card adaptor having a register group based on an interface generally used in communication through a serial port interface and a network adaptor. Furthermore, when a small memory card is inserted, it is necessary to set a small card adaptor having a register group based on the PC card ATA standards interface.
However, with the above-mentioned configuration, a complicated controller or a large-scale control program for controlling so that the processing for a small communication card and the processing for a small memory card can be performed in a small card adaptor. As a result, the capacity of a memory storing it is increased, and the number of gates of a controller provided in a small card adaptor is increased. Thus, a small card adaptor becomes expensive.
Therefore, with the foregoing in mind, it is an object of the present invention to provide a small card adaptor in which driver software for a small card inserted in a small card adaptor is changed appropriately so as to operate normally, whose a production cost is decreased, and a host apparatus into which the small card adaptor is inserted.